Computes the average of a variable's given dimensions at all other dimensions and retains metadata.
Available in version 5.1.1 and later.
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl" function dim_avg_n_Wrap ( x : numeric, dims [*] : integer ) return_val : float or double
A variable of numeric type and any dimensionality.dims
The dimension(s) of x on which to calculate the average. Must be consecutive and monotonically increasing.
The output will be double if x is double, and float otherwise.
The output dimensionality will be the same as all but dims' dimensions of the input variable. The dimension rank of the input variable will be reduced by the rank of dims.
Create a variable (q) of size (3,5,10) array. Then calculate the average of the rightmost dimension.
q = random_uniform(-20,100,(/3,5,10/)) qAvg = dim_avg(q) ;==> qAvg(3,5)Example 2
Let z be of size (ntim,nlat,mlon) and with named dimensions "time", "lat" and "lon", respectively. Then, for each time and latitude, the zonal mean (i.e., average of all non-missing longitudes) is:
zAvgLon = dim_avg(z) ; ==> zAvgLon(ntim,nlat)Generally, users prefer that the returned variable have metadata associated with it. This can be accomplished via the dim_avg_Wrap function:
zAvgLon = dim_avg_Wrap( x ) ; ==> zAvgLon(time,lat)Example 3
Let z be defined as in Example 2: z(time,lat,lon). Compute the time average at each latitude/longitude grid point.
zAvgTime = dim_avg_n( z, 0 ) ; ==> zAvgTime(nlat,nlon)If metadata is desired use:
zAvgTime = dim_avg_n_Wrap(z,0) ; ==> zAvgTime(lat,lon)Example 4
Let z be defined as z(time,lev,lat,lon). Compute the time/level average at each latitude/longitude grid point.
zAvg = dim_avg_n(z,(/0,1/)) ; ==> zAvg(nlat,nlon)If metadata is desired use:
zAvg = dim_avg_n_Wrap(z,(/0,1/)) ; ==> zAvg(nlat,nlon)